Problem: In 42 years, Omar will be 3 times as old as he is right now. How old is he right now?
Answer: We can use the given information to write down an equation about Omar's age. Let Omar's age be $o$ In 42 years, he will be $o + 42$ years old. At that time, he will also be $3 o$ years old. Writing this information as an equation, we get: $o + 42 = 3 o$ Solving for $o$ , we get: $2 o = 42$ $o = 21$.